Authorities say hikers have found a human foot inside a man's shoe while walking along the western banks of the Mississippi River in the St. Louis area.

St. Louis County police said in a news release Monday that the discovery was made on Labor Day in Bee Tree County Park. Police say nothing additional "of value" has been found despite helicopter and water searches. Cadaver dogs also have been used to comb the area.

It's not clear how long the foot had been there. The shoe is red and between sizes 11 and 14.